Recently a housemaker called the OU’s front desk, concerned that her non-Jewish help had just used kosher red wine vinegar to prepare a salad dressing. Is the dressing, and the red wine vinegar, still kosher? To put this question in other terms: is red wine vinegar, like non-mevushal wine, subject to the laws of מגע עכו“ם, which would mean that if a gentile handles the wine it is rendered non-kosher?
Does wine vinegar present a concern of stam yainam(wine touched by a non-Jew)?
I happened to be standing around the front desk, and the receptionist relayed the question to me. My inital response was that of course it is not a problem. It just so happens that I am learning the second perek of Avodah Zorah, and the gemara teaches that kosher wine vinegar that is touched by a gentile is not rendered non-kosher. However, it’s critical not to respond immediately to questions you’ve never been asked before, and certainly not to answer anything based only on what the gemara says.
In fact, Tosefos (29b) notes that there is no longer a concrete way of distinguishing between wine and wine vinegar, and therefore we don’t have what we, in contemporary terms, would call a “standard of identity” for wine vinegar. The Rashba agrees that much of what people call wine vinegar may not be unambiguously vinegar. He does establish a criterion for determining whether or not “vinegar” is actually that: if one were to pour it on the floor and it would be מבעבוע, then we can rest assured that the substance is definitely red wine vinegar. Shulchan Aruch (123,x) adopts this ruling.
What does מבעבוע mean? That itself is a good question. Literally, the word means that the substance is bubbling, active, or somehow not still. Vinegar us the result of fermentation, which is a bioactive process that one might be able to actually observe. One mesorah apparently holds that if a haze has developed immediately above the surface of the liquid then it has fulfilled this criterion. חכמת אדם states that we are no longer able to make this evaluation.]
Clearly, our table vinegar does not create a haze, nor does it seem bio-active in any readily identifiable way. However, table vinegar is simply a diluted form of vinegar, or acetic acid. If industrial, undiluted vinegar is מבעבוע, then what would now be bona fide vinegar would remain vinegar even if it was then diluted and no longer מבעבוע.
There is no question that the production of wine vinegar creates a significant amount of vapor. In fact, the widespread practice of vinegar companies to capture vapor, dilute it, and reuse it is something that a mashgiach must be aware of (he has to know where that recaptured vapor is going). However, the actual production of vinegar involves agitation of the vinegar and is also hidden in a production tank, which makes it difficult to observe the vinegar-production process.
Several years ago I stood on a railing above a gigantic nono-kosher red wine vinegar storage tank and looked down towards the vinegar. The vinegar, which was about fifteen feet below my face, was so strong that the vapors instantly condensed in my mouth, and I had to spit out the liquid into my hand. However, the liquid itself was certainly still, and there was nothing unusually active or bubbly about it.
A few weeks after the consumer inquiry I found myself in another vinegar company. I asked for a sample of their strongest wine vinegar. Their vinegar is made from wine that is 16 percent alcohol — pretty strong wine, which means that the vinegar should also be pretty strong. However it certainly did not create a haze, or bubble, or seem at all remarkable (I brought back a sample to New York, making sure that there was less than three ounces remaining, so that I could pass through TSA).
So, it is not clear at all whether any of the vinegar that we have in contemporary times is מבעבוע unless the criterion one uses is that there is a haze. The חכמת אדם in any event, states that we are no longer capable of making this evaluation.
Now, to get back to the original question: all OU wine vinegars use wine that is originally מבושל (boiled or pasteurized) so there is no longer any concern of מגע עכו“ם. So, if a gentile were to handle such vinegar it would remain kosher.